Diastolic measurements from alternate R-wave gating of radionuclide angiograms

Systolic and diastolic cardiac dysfunction early after the initiation of doxorubicin therapy: significance of gender and concurrent mediastinal radiation

Diastolic and systolic left ventricular (LV) function may be affected early after the initiation of doxorubicin therapy. However, the role of mediastinal radiation and other cytotoxic agents in the production of these early cardiac effects is unclear. In this study LV diastolic and systolic function were assessed before and after doxorubicin (223+/-122 mg.m-2; range, 40-618) in 33 patients. After doxorubicin, LV ejection fraction declined (0.61+/-0.08 to 0.56+/-0.08, P=0.0008), peak filling rate decreased (3.38+/-1.10 to 2.82+/-0.62 end diastolic volumes/s, P=0.006), and time to peak filling rate increased (162+/-39 to 182+/-45 ms, P=0.04). The changes in LV systolic and diastolic function were not related to doxorubicin dose and the use of other cytotoxic agents; the decrease in LV ejection fraction with doxorubicin was more notable in men and in patients who received mediastinal irradiation concurrently with doxorubicin. It is concluded that the use of doxorubicin was associated with the simultaneous early development of LV systolic and diastolic dysfunction. Male gender and concurrent mediastinal irradiation were independent influences, but doxorubicin dose and the use of other cytotoxic agents were not associated with worse cardiac dysfunction.

Effect of metoprolol on rest and exercise left ventricular systolic and diastolic function in idiopathic dilated cardiomyopathy

OBJECTIVE

To further characterize the effects of heart rate on systolic and diastolic function in patients with idiopathic dilated cardiomyopathy (IDCM), it was hypothesized that the relationship between heart rate and left ventricular systolic and diastolic function would be unaltered by beta-blockade and exercise.

METHODS

Eighteen patients with IDCM were randomized in a double-blind manner to receive either metoprolol or placebo for 3 months. Before and after 3 months of therapy, resting and exercise radionuclide left ventriculograms were obtained for assessment of left ventricular systolic and diastolic function.

RESULTS

At rest, metoprolol treatment compared with placebo was associated with decreased heart rate (61 +/- 11 vs 99 +/- 10 beats/min, P <.0001) and an increased left ventricular ejection fraction (0.32% +/- 0.10% vs 0.17% +/- 0.08%, P =.01). With exercise, metoprolol compared with placebo caused a decreased heart rate (86 +/- 18 vs 126 +/- 43 beats/min, P =.056), an increase in left ventricular ejection fraction (0.32% +/- 0.14% vs 0.19% +/- 0.07%, P =.052), a longer time to peak filling rate (164 +/- 21 vs 127 +/- 17 ms, P =.005), and a decreased peak filling rate (5.41 +/- 1.71 vs 8.40 +/- 1.85 stroke volumes/s, P =.012). Before beta-blockade, heart rate at rest was negatively correlated to left ventricular ejection fraction and positively correlated to peak filling rate; with exercise, the relationships of heart rate to left ventricular ejection fraction and peak filling rate were similar. After metoprolol treatment, the heart rate continued to have a similar positive correlation with the peak filling rate at rest and with exercise.

CONCLUSIONS

In patients with IDCM, systolic and diastolic cardiac function, at rest and with exercise, was related to heart rate. After beta-blockade, at rest and with exercise, diastolic function continued to be related to heart rate.

Resting heart rate and cardiac function in dilated cardiomyopathy

We hypothesized that, within the normal range of resting heart rate, heart rate and left ventricular ejection fraction would be inversely correlated and heart rate and left ventricular filling would be correlated in patients with dilated cardiomyopathy and not correlated in patients with normal cardiac function. At rest, heart rate, left ventricular ejection fraction, and three measures of diastolic filling (time to peak filling rate, peak filling rate, and first half filling fraction) were recorded using radionuclide ventriculography in subjects with no cardiac disease, patients with idiopathic dilated cardiomyopathy, and patients with dilated cardiomyopathy associated with ischemic heart disease. Heart rate had significant inverse correlations with left ventricular ejection fraction (r=-0.55, P=0.0007) and time to peak filling rate (r=-0.47, P=0.005) and a positive correlation with peak filling rate (r=0.73, P<0.0001) in patients with idiopathic dilated cardiomyopathy; heart rate was correlated only weakly with these measures in the absence of cardiac disease and essentially was not correlated in dilated cardiomyopathy due to ischemic heart disease. The change in resting heart rate with left ventricular ejection fraction and time to peak filling rate were significantly (P<0.05) different between patients with no cardiac disease and those with idiopathic dilated cardiomyopathy. Thus, resting heart rate correlated significantly with left ventricular ejection fraction and diastolic filling in patients with idiopathic dilated cardiomyopathy.

Influence of left ventricular diastolic filling on symptoms and survival in patients with decreased left ventricular systolic function

The relation between left ventricular (LV) filling variables measured by gated blood pool radionuclide ventriculography and clinical symptoms and survival was examined in 93 patients who had decreased LV systolic function. The diastolic data were not significantly associated with clinical symptoms. Time to peak filling rate, peak filling rate and ejection fraction were associated independently with survival free of cardiac death (chi-square = 7.74, 5.91 and 3.92, respectively, by stepwise Cox regression analysis). A short time to peak filling rate or increased peak filling rate was associated with decreased survival, whereas the opposite indicated a good prognosis. One-year Kaplan-Meier survival was 73 and 98% when time to peak filling rate was below or above the median value of 167 ms, respectively, 82 and 90% when peak filling rate was above or below the median value of 1.67 end-diastolic volumes per second, respectively, and 76 and 95% when LV ejection fraction was below or above the median value of 0.35, respectively. Thus, filling variables (time to peak filling rate and peak filling rate) measured by radionuclide ventriculography may be valuable in predicting survival in patients with decreased LV systolic function.

Determination of diastolic function by radionuclide ventriculography

Diastolic filling can be measured by radionuclide ventriculography with use of several techniques including those based on gated and list-mode acquisitions, the first-pass method, and the nuclear probe. Radionuclide ventriculography specifically assesses volumes, rates of volume change, and intervals during ventricular filling. Normal values for diastolic filling measurement vary depending on the individual radionuclide methods used and the age of the patient. Comparative studies of the radionuclide method with contrast angiographic and Doppler echocardiographic techniques for measuring diastole are discussed, and the advantages and disadvantages of the radionuclide techniques are explored. The role of radionuclide assessment of diastolic function in specific clinical examples of hypertrophic cardiomyopathy, hypertension, anthracycline-induced cardiomyopathy, and coronary artery disease is reviewed. Radionuclide ventriculography is an accurate and easily applicable procedure for studying left ventricular volume changes in diastole.

Influence of age and sex on left ventricular filling at rest in subjects without clinical cardiac disease

Left ventricular (LV) filling at rest was studied by radionuclide ventriculography using alternate R-wave gating in 42 patients (29 men, 13 women) who had a low likelihood of cardiac disease. LV filling measurements differed little between men and women. Age was correlated positively with atrial filling duration (r = 0.55), atrial filling duration fraction (r = 0.52) and atrial filling fraction (r = 0.56) and negatively with rapid filling fraction (r = -0.58). Age was not correlated with peak filling rate, time to peak filling rate and first-half filling fraction. The heart rate at rest was significantly negatively correlated with rapid (r = -0.62), slow (r = -0.81) and atrial (r = -0.72) filling durations, but not with isovolumic duration. The heart rate at rest was weakly positively correlated with peak filling rate in end-diastolic volume per second (r = 0.36) and negatively correlated with first-half filling fraction (r = -0.35). Systolic pressure at rest influenced atrial filling duration. LV ejection fraction and end-diastolic volume index were not correlated significantly with LV filling in relatively normal subjects.